Physical exercise and the prevention of disability in activities of daily living in older persons with osteoarthritis

Background: The prevention of disability in activities of daily living (ADL ) may prolong older persons' autonomy (older persons are defined in this st udy as those aged 60 years). However, proved preventive strategies for ADL disability are lacking. A sedentary lifestyle is an important cause of disa bility. This study examines whether an exercise program can prevent ADL dis ability. Methods: A 2-center, randomized, single-blind, controlled trial was conduct ed in which participants were assigned to an aerobic exercise program, a re sistance exercise program, or an attention control group. Of the 439 commun ity-dwelling persons aged 60 years or older with knee osteoarthritis origin ally recruited, the 250 participants initially free of ADL disability were used for this study. Incident ADL disability, defined as developing difficu lty in transferring from a bed to a chair, eating, dressing, using the toil et, or bathing, was assessed quarterly during 18 months of follow-up. Results: The cumulative incidence of ADL disability was lower in the exerci se groups (37.1%) than in the attention control group (52.5%) (P=.02). Afte r adjustment for demographics and baseline physical function, the relative risk of incident ADL disability for assignment to exercise was 0.57 (95% co nfidence interval, 0.38-0.85; P=.006). Both exercise programs prevented ADL disability; the relative risks were 0.60 (95% confidence interval, 0.38-0. 97; P=.04) for resistance exercise and 0.53 (95% confidence interval, 0.33- 0.85; P=.009) for aerobic exercise. The lowest ADL disability risks were fo und for participants with the highest compliance to exercise. Conclusions: Aerobic and resistance exercise may reduce the incidence of AD L disability in older persons with knee osteoarthritis. Exercise may be an effective strategy for preventing ADL disability and, consequently, may pro long older persons' autonomy.